Sheet holding and straining device.



Patented Aug. |899. w. sPALcKHAvER.

SHEET HOLDING AND STBAINING DEVICE.

, (Application led. Dec. 10, 1898.)

(No Model.)

2 Sheets-Shen I.

No. 629,933. Patented Aug. l. 899.

w. sPALcKHAvEn. SHEET HOLDING AND STBMNING DEVICE.

A (Application met( Dec. 10, 1898.) l(No Model.) l2 Sh99t9-$heet 2.

UNITED Y STATES PATENT Orricn. n,

XVILIAM SPALCKHAVER, OF NEYV YORK, Y., ASS'IGNOR TO ROBERT HOE, TlllllODORE, H. MEAD, AND CHARLES W'. OARPENTER, OF SAME PLACE.

SHEET HoLDiNe AND srnninirm nevica.

SPECIFICA???QN'` forming part of Letters Patent No. 629,933, dated August 1, 1899.

Application tiled ecember l0, 1898. Serial Noi 698,864. (No model.)

accompanying drawings, forming a part of xo the same.

Thisinvention relates to improvements in holding and straining devices for sheet material, and is more particularly directed tou ward improvements in those devices lwhich 15 are intended to strain to their seat-s and hold' in position sheet-metal printing-platesil-such1l for instancelas those made from aluminium, zinc, and other similar material.

In holding and strainingr printing-plates zorsuch as have been beforereferred toand ot-her sheet material to their supporting-surfaces it isfrecpiently necessary to subject certain parts 'of the sheets or plates to greater tension than other parts in order to .cause 25 Vthem to lie evcnlyand smoothly upontheir supportingsurfaces.V l `iirthermore, when i such plates are mounted upon cylinders it is desirable to make the gaps in Ithe cylinders narrow in order that as much of the surface 3c of the cylinders as possible may be covered by the plates, or rather to make the intervals between the plates as 'small as possible.

The objects of this invention are to produce a plate-clamping device which shall be 35 cheap to construct', which can be easily and readily manipulated, which can be adjusted to give certain parts of the plate greater tension than other parts, and which shall be of such a character that a small opening or gap 4o in the cylinder will afford su iiicient space for its location and manipulation. With these and other object-s in view the invention consists in certain constructions and incertain parts, improvement-s, and com- 45 binationsmhichwillbehereinafterdescribed, and fully pointed'out in the claims hereunto appended.

In the accompanying drawings, which represent concrete embodiments of the invention 5o 'and inwhich like charactersof reference in-y dieate the .same parte, `l4"ig'ure 1 indicates' 'a respect thereto.

portion of a plate-carryingcylinder, partially in section, equipped with one form of 'the im'- proved holding and straining devices.l Fig.

2 is a section on kthe line 2 2 of Fig. 1 and 55 looking in the direction of thearrcw in said figure. Fig. 3 is a section on the line 3 3 of Fig. 2, looking in the direction of the arrows in said figure. Fig. eis a detail perspective view showing the relative location of one of 6oy the jaws and the abutment. Figs. 5 and 6 are respectively detail plan and sectional views of a modification of the improved holding and strainilgfdevices. l

. Referring to the drawings, 1 indicates a por- 6 5 tion of an impression-cylinder carrying a sheet-metal printing-plate 2 andhaving the usual gap 3 for the holding and straining devices.` uitabl'y located in the Acylinder' with K respect to the gap 3 is ashaft 4,Which is pre- 7o vided with suitable means for turning the Y. saine-as, for instance, a squared head 5, though any other suitable meansmay be einployed. The shaft preferably extends from side to side of the cylinder and nds its bear- 75 ings in plates G, which are secured'to the cylinder by bolts 7v or in any other suitable manner. The shaft is provided with any suitable devices forpreventing its rotation, except when it is turned by a Wrench-applied to the 8o squared head or in any-other suitable Inanner. The device shown for preventing it from turning is a ratchet-wheel 8, which'is yengaged by a pavvl 9, suitably pivotedon the plate 6 and held to its duty byan ordinary 85 plate-spring 10. v Y

The shaft 4 is preferably provided with a series of abutments which are stationary With These abutments are preferablyin the form of collars 11, which are se- 9o cured to the shaft by means of keys 12 and having projecting ribs 13.

' The gripping devices,ot which there are preferably a series and which maybe of any suitable form, preferably consist of a'series 95 Y of pairs of jawsywhich are mounted on the shaft 4.l The lower jaw 14; of. the lgripping devices is provided with a pair of collars 15, whichmay be located at each end of thejan and which loosely embrace the shaft. jaws l have downwardlyprojecting portions 16, whichlie in frontof theribs 13 of the abut- These mr,

ments .11, said projections being provided with threaded apertures 1G', for a purpose to' be hereinafter described. The' collars 15 have thickened portions 17, which are also 'provided with threaded apertures 17 In the preferred form of the invention the jawr which .coperates with the jaw 14` con-A sists of a plate y18. This plate rests against the side of the jaw 14 and has an overhanging portion 18', which forms the upper jaw. The plate is provided with projectingxportions- 19, havingsuitable apertures therethrough. Located in the threaded apertures '-17,before referred to, are apertured projections, which preferably take the form of y threaded screw-eyes 20. The threaded screweyes pass through apertures 21 in the plate 18, these apertures being sufficiently large to allow the plate 1S to have. a slight vertical movement. i

' The jaws are drawn together by means of screws 22,'which pass through the aperture in the projection 19 and engage the threaded 'aperture in the projection 20, these screws having squared heads to enable them-to be engaged by a suitable wrench introduced In order to carry out the invention, means must be provided for-forcing the jaws away from the abutment ih front of which they are located, and these /means may be of various kinds. Preferably, however, they willconsist of 'screws 24, which pass through the jawl plate 18, engage the threaded aperture 16 in the jaw 14, and bear against the rib 13 of the abutment 11. Itbeing remembered that there are a series of clamping devicesv mounted on the shaft 4, the operation ofthe straining and holding mechanism as a whole will be obvious.

l The edge of the sheet isv introduced between t'liej'aws 1S and 14.

l l l 'lhe said jawswilltheu be forced together by means of the screws 22, and when the plate has been securely clamped fthe screws 23'are adjusted to hold the jaws in position.- The screws 24 are then turned by any suitable means, andea'ch pair of jaws is thus adjusted away from the stationary abutment, the loose engagement of the collars 15 with the shaft 4 permitting thejaws to turn about the axis of the shaft. By adjust-- ing the screws 24 of each pair of jaws a greater or less amount the tension on the various parts of the plate can be varied as desired.

lVhen the adjustment of the several jaws.'

along the shaft has been effected, the shaft is turned by a wrench or other suitable means,

thus carrying the `abutmentsand thejaws away.fro1n the edge of the plate-supportingY surface of the cylinder and drawing the plate securely to its seat on the cylinder. .The other end ot-the plate may be held inany desired manner.v It is' here shown as held by means of arms 25, mounted on a shaft 26, which is parallel to'the shaft 5, said shaft being kept in position`- to hold the arm against the edge of the cylinder by any suitable mea-ns, as by a spring. (Not shown.)

In the modification illustrated in Figs. 5 and 6 the upper jaw instead of lconsisting'of a plate 1.8 is formed from a block or casting 27, which has an-offset portion thereon engaging an offset portion on the jaw 14, the said jaw'being forced down on the lower jaw byscrews. In other'respects this modification is the same as that heretofore described and the operation is the same. .j

Various modifications of the construction other than those illustrated are possible. The

holding-jaws and thev abutments may be mounted in various ways so long as the jaws can be given an' adjustment with relation to` the abutments and the abutments and jaws moved together away from the plate-supporting surface. sorted to for forcing 'the jaws together other Various means may also be re than those-described, and in general many' other modifications may be made which will .suggest themselves to skilled mechanics.

Furthermore, while the invention is particularlyadapted for'holding sheet-metal plates on cylinders it is capable of use inmany other relationsas,for instance, for holding various other kinds of sheet material,` such as-printers blankets, andfor holding sheets ofjal-l descriptions in position on other than cylindrical surfaces-as,for instance,on dat beds. While,- also, in the preferred formof the invention loo a series of jaws and abutments'are used, a

4single long abutment and a single pairof jaws may be used.' he invention is not therefore to be limited to the Iparticular form of mech-y anism described nor to the particular use described, but is to be regarded as embracing all modifications which fall within its spirit and scope as defined in the claims hereunto appended.

What I claim is- 1. Ina sheet holding and. straining device,

the combination with a sheet-supporting surface, of an under jaw, a plate resting against said jaw'and having an overhanging portion which forms an upper jaw, and means for respect `to the under jaw, whereby t he.two jaws are forced together, s ubstantiallyas described. v

,2. In a sheet holding and straining device, I the combination withacylindrical sheet-sup.-

porting surface having a gap therein, an under jaw located in the gap, aplate resting against the under jaw'and having .an overhanging portion forming an upper jaw, and means located in the gap for givingthe plate Vgiving the plate a sliding movement with',v

a sliding moveme'utwith respect to the under jaw, whereby the jaws are forced together, substantially as described, A 5

3. In a sheet holding and straining device, the combination with a cylindrical sheet-sup porting surface having a gap therein, an uuder jaw located in thev gap, a plate resting against the under jaw and having an over- Ihangingportion forming an upperjaw, means located in the gap for giving theplate a sliding movement with respect vto theuuder jaw,

and means for forcing the jaws away from' lthe sheet-supporting surface, substantially as described.

4; In a sheet holding and .straining device, thezcombination with a sheet-supporting surface, of an under jaw, a plate resting against said jaw and havingan overhanging portion forming an upper jaw, a` projection on each,

of the jaws, and means engaging the projections and coperating therewith ,to give the plate a sliding movement with respect tothe under jaw to force the jaws together, substanj tially as described.

5. In a sheet holding and straining device,.. the combination with a sheet-supporting surface, of an under jaw, a plate restingagainst said jaw and having an overhauging portion forming an-npper jaw, a projection. on each of the jaws, means engaging the projections andcoperating therewith to give the plate a -sliding movement with respectto the-under jaw to force the jaws together, and means for forcing the jaws away from the sheet-supporting surface, substantially as described. v 6. In a sheet .holding and straining device, the combination with a sheet-supporting su rface, of a pair of jaws, means foi' forcing the jaws together to grip a sheet, an abutment, means for `forcing the jaws away from the abutment, means for adjusting the abutment and the jaws with respect to the supporting-A surface and means for holding the other'edge of the plate in opposition to the movement of the jaws and abutment, substantial-lyas described.

7. In a sheet holding and straining device,

the combination with a sheet-supporting surface, o f a' series of pairs of jaws, means for forcing'the jaws together to grip a sheet, a-

series of abutments, means for forcing the jaws away from the'abutments, means for adj'usting the abntments and the jaws with respect to the supporting-surface and means for holding the other edge of the plate in opposition 'to the movement of the jaws and abutments, substantially as described.

8, In a sheet holding and straining device,

the combination with a pairof jaws, of means .for forcing the jaws together to grip the sheet,

a shaft upon which thejaws are mounted, an abutment on the shaft 'and stationary with respect thereto,lmeans whereby the jaws areforced away from the abu tmennmeaus whereby the shaft may be rotated and means for holding the opposite edge of the plate in opposition to the movement of the jaws and the combination with a series of pairs of jaws,

of means for forcing the jaws together to grip a sheet, a shaft upon which the pairs of jaws vare mounted, a series ofabutments on the shaft and stationaryv with respect qthereto,

vmeans whereby the jaws are forced away from the abutment-s, means whereby the shaft may be rotated to adjust the ab'u tments and the jaws, and means for holding theopposite edge of the plate in opposition to the movement of the jaws and abutments produced by the rotation of the shaft, substantially as described.

' l0. In a sheet holding and straining device, the combination witha shaft having an abutment thereon, of a jaw mounted on the shaft and having a projection which lies in front of the abutment, meanscarrie'd by the projection andengaging the abutment for moving the jaw away from the abutment, a seccndjaw, means for forcing the two jaws together to clamp a plate, means for rotating the shaft, and means for holding the opposite edge of the plate against the movement of the 'for forcing the jaws together to clamp a plate,

means whereby thev shaft maybe rotated and means for holding the opposite edge of plate .against the movement of the jaws and abutm'ents produced by the rotation of the shaft, substantially as describedfV 3 l2. In a sheet holdiugvand straining device, the combination with 'a shaft, of a collar se- ,cu red thereto having a projection which forms an abutment, a jaw provided with a pair of collars which loosely surround the shaft on each side of ,the stationary collar, means for forcing the jaw away from the abutment', a

IIO

second jaw and means for forcing the two:- jaws together to grip the sheet, substantially j as described.

13. In a sheet holding and straining device,

the combination with a shaft, of a series of v collars secured thereto and havin g projections which form abutment-s, a series of jaws pro vided with a pair of collars which loosely snrronnd Ithe shaft on each side of the stationary collars, means for forcing the jaws awayV from the abntinents, a second series of jaws;v means for forcing the jaws together to grip the sheet, and means whereby the shaft may be rotated, substantially as described.

lll. in a sheet holding and straining device,

the combination with a shaft having an abutment thereon, of a jaw provided with a pair of collars which loosely embrace the shaft' on i cach side of the abutment, means for forcing .thc jaw away from the abutment, a second .the combination with'a shaft having a series 5 of abutments thereon, of a series of jaws prol vided with a pair of collars which loosely embrace the shaft on cach side of the abutments,

means for forcing the jaws away from the abntmen ts, a second series of jaws, screws for forcing the jaws together' to clamp a-sheet, and means whereby the shaft may be rotated, substantially as described.

16. -In a sheet holding andstraining device,'

the combination with a sheet-supporting surface, of an abutment, a jawmounted so as to be movable with respect to the abutment, means for forcing the jaw away from the abutment, a second jaw carried bythe first-named jaw, projections connected to each of the jaws and means engagingsuch projections for forcing the jaws together, substantially as described.

17. In a sheet holding and straining device,

.the combination with a sheet-supporting su rface, of a series of abutment's, a series of jaws mounted sc as to be movable with respect to the abutments, means for forcing the jaws away from-the ahutments, a second series of jaws carried by the first-named jaws,I projections connected to the jaws of each series,-

,saaes i tions, projections mounted on the thickened portions, a second jaw,projcctions on said jaw, nica-ns engaging the project-ion on the jaw and I the projection on the collars for forcing the i jaws together, and means for forcing the jaws f away from the abutment, substantially as described.

1U. In a sheet holding and strainingdevice, the combination with a shaft, of a series of abutments mounted thereon, a series of jaws having collars embracing the shaft on; each side of the abutments, said collars having thickened portions, projections mounted on the thickened portions,a second series of jaws, projections on said jaws, means engaging the on the collars for forcing the jaws together, means for forcing the jaws away from the abutments, and means wherebythe shaft may be rotated, substantially as described. 20. In a sheet holding and straining device, the combination with a shaft, of a series of abutments stationary thereon, a series of jaws having collars loosely embracing the collars on each'side of the abutments, said collars having thickened portions, a second series of jaws having portions overhanging the first series ofjaws, projections in the form of screweyes engaging the thickened portions of the collars, projections extending from each of the second series of jaws, screws passing through one set of the projections and engaging the other set for forcing the jaws together, screws for-holding the jaws firmly in their adjusted position, andscrews for forcing the jaws away from the abutments, and means whereby the shaft may be rotated, substantially as described.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses. -v

WILLIAM SPALCKHAVER. Tit-messes:

F. W. H. CRANE, E. L. SPEIR.

projections on the jaws and the projection 

